package io.github.dunwu.javacore.jdk8.concurrent;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ForkJoinPool;

/**
 * @author Benjamin Winterberg
 */
public class ConcurrentHashMap1 {

	public static void main(String[] args) {
		System.out.println("Parallelism: " + ForkJoinPool.getCommonPoolParallelism());

		testForEach();
		testSearch();
		testReduce();
	}

	private static void testForEach() {
		ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
		map.putIfAbsent("foo", "bar");
		map.putIfAbsent("han", "solo");
		map.putIfAbsent("r2", "d2");
		map.putIfAbsent("c3", "p0");

		map.forEach(1, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value,
			Thread.currentThread().getName()));
		// map.forEach(5, (key, value) -> System.out.printf("key: %s; value: %s; thread:
		// %s\n", key, value,
		// Thread.currentThread().getName()));

		System.out.println(map.mappingCount());
	}

	private static void testSearch() {
		ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
		map.putIfAbsent("foo", "bar");
		map.putIfAbsent("han", "solo");
		map.putIfAbsent("r2", "d2");
		map.putIfAbsent("c3", "p0");

		System.out.println("\nsearch()\n");

		String result1 = map.search(1, (key, value) -> {
			System.out.println(Thread.currentThread().getName());
			if ("foo".equals(key) && "bar".equals(value)) {
				return "foobar";
			}
			return null;
		});

		System.out.println(result1);

		System.out.println("\nsearchValues()\n");

		String result2 = map.searchValues(1, value -> {
			System.out.println(Thread.currentThread().getName());
			if (value.length() > 3) {
				return value;
			}
			return null;
		});

		System.out.println(result2);
	}

	private static void testReduce() {
		ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
		map.putIfAbsent("foo", "bar");
		map.putIfAbsent("han", "solo");
		map.putIfAbsent("r2", "d2");
		map.putIfAbsent("c3", "p0");

		String reduced = map.reduce(1, (key, value) -> key + "=" + value, (s1, s2) -> s1 + ", " + s2);

		System.out.println(reduced);
	}

}
